First Teeth Grew on the Outside of the Body

The tooth-like lip and cheek scales were found in specimens of ischnacanthid acanthodians similar to this one from the University of Alberta Laboratory for Vertebrate

• New research on Early Devonian fish suggests that the world's first teeth evolved outside of the mouth.
• Scales on the exterior of the prehistoric shark-resembling fish appear to have evolved into teeth.
• Teeth were retained among most vertebrates and were passed down to multiple species, including humans.

The fictional Cheshire cat's smile seemed to have a life of its own, outside of the cat's body, and now new research suggests the world's first teeth grew outside of the mouth before later moving into the oral cavity.

The study, published in the Journal of Vertebrate Paleontology, supports what is known as the "outside-in" hypothesis of tooth evolution. The first teeth and smile, however, did not belong to a cat, but likely were flashed by small and spiny shark-like fishes.

That initial smile would have looked rather sinister.

"The first smile would probably have been a prickly one, with many tiny teeth that looked like pointy cheek scales, and other small tooth-like scales wrapping around the lips onto the outside of the head," co-author Mark Wilson told Discovery News.

For the study, Wilson, a professor in the Department of Biological Sciences at the University of Alberta, and his colleagues studied animals called ischnacanthid acanthodians, an extinct group of fish that resembled sharks.

They lived during the Early Devonian period, which lasted from 416 to 397 million years ago.

The researchers determined that head scales from these fish were in transition, evolving from scales to teeth. The pointy structures were identified on the lips of the fish.

This discovery helps to negate the “inside out” theory of tooth evolution, which holds that the first teeth emerged from structures in the pharynx progressing into the mouth.

Project leader Stephanie Blais, a University of Alberta researcher, told Discovery News that "our findings support the idea that teeth evolved from modified pointed scales on the mouth margins (lips) as we see in Obtusacanthus," one of the prehistoric fish included in the study.

All of the analyzed fish specimens were excavated at the Man on the Hill site in the Mackenzie Mountains of Canada.

As to why teeth first evolved, Blais said they "would have conferred a major advantage in terms of food acquisition. Pointed scales near the margins of their mouths would have helped them grasp prey and hang on to it until they could swallow it whole."

Such prey consisted of "probably whatever they could swallow," co-author Lindsay MacKenzie of the University of Montana’s Department of Geosciences told Discovery News.

Based on fossilized stomach contents and other evidence, their primary prey probably consisted of arthropods, including crustaceans, as well as a variety of soft-bodied creatures and fish.

Blais said jaws, which must have evolved earlier, and the tooth-like formations "allowed fishes to change from a filter-feeding or mud-grubbing more passive lifestyle to one of active predation."

The world's first aggressive conflicts also may have arisen at this point, since the move from passive feeding to hunting led to what Blais termed "the very first evolutionary arms race" among vertebrates, with some becoming predators and others becoming prey.

Dinsaur Bones: Near-Perfect Fossil on Display in Munich

German paleontologists have discovered what they believe is the best-preserved dinosaur skeleton ever found in Europe.

Some 98 percent of the fossil found in the southern state of Bavaria is intact, and it will soon be placed on display for a short time in Munich.

The discovery of young, unnamed dinosaur fossils is rare, but on Wednesday researchers in southern German state of Bavaria announced they had uncovered an almost perfect specimen.

The flesh-eating member of the theropod subgroup, which walked on its hind legs, is among the best preserved specimens of its kind worldwide, said Oliver Rauhut, conservator of Bavaria's state paleontological and geological collections (BSPG) in Munich.

The fossil found in the central Bavarian community of Kelheim is about 98 percent complete, and also includes preserved bits of skin.

"The around 135-million-year-old fossil is of outstanding scientific importance," dinosaur expert Rauhut told the German news agency DPA.

A number of similar fossils have been found in China, he said, but they are not as well-preserved. "From far away they often look complete," he said. "But up close one sees that the bone preservation is not that great."

On Display in Munich 
Though the 72-centimeter juvenile dinosaur is preserved in stone, a number of anatomical details remain.

"The best-preserved Tyrannosaurus we have are about 80 percent preserved, and that is already terrific," said Rauhut, comparing the two theropods, which are among the rarest dinosaur fossils.

Most of the fossils in this group exist in only fragments, said Dan Ravasz, spokesman for the upcoming mineral exhibition, The Munich Show, a trade fair dedicated to minerals, germs, jewellery and fossils that runs for four days starting on Oct. 27.

The experts aren't certain just how old the dinosaur was when it died, though they estimate that a freshly hatched Tyrannosaurus would have been about the same size.

They were able to determine that the specimen is young by measuring the size of its skull, body proportions and the bone surface.

Learning more about young dinosaurs is important for scientists to understand more about their evolutionary process.

The fossil, discovered between one and two years ago, has been registered as a German cultural asset, giving it a status that drastically lowers its monetary worth, but ensures the artefact will remain in the country.

Ravasz declined to reveal the exact location of the discovery or its owner, but said it would later be loaned to a museum.

Ancient Protein Found in Sea Lizard Fossil

IMAGE 1: Clidastes propython, a mosasaur from the Late Cretaceous of Kansas (Wikimedia Commons).

The world is one step closer to Cretaceous Sea World, the aquatic version of Jurassic Park.

Tissue from a 70-million-year-old marine lizard was recently extracted from ancient remains by a team from Lund University in Sweden.


IMAGE 2: Bone matrix fibrils, or small fibers, in mosasaur bone: (a) Histologic preparation that shows how the fibers surrounds a vascular duct. (b) SEM-picture that shows etched fibers. (c) Detail of histologic preparation showing fibers encapsulated in bioapatite. (d) Histo-chemical stain (blue) showing that the fibers contain biological matter. (Credit: Photo by Johan Lindgren)


Collagen protein, a type of connective tissue, was found inside the fossilized upper forelimb bone of the mosasaur Prognathodon, a long-dead relative of the monitor lizard.

While this is not the first time proteins have been recovered from dinosaur-era remains, this is the first find of preserved tissues from a marine environment. And the first time they have been found in place in a fossil.

Earlier finds came from extracts of whole dinosaur bones preserved in sediments from what were once river floodplains.


In the journal PlosOne, the Swedish scientists detail their new mosasaur find. The researchers note that the earlier ancient protein extractions have been controversial, but note that their new research is backed up by several tests to corroborate the tissue's authenticity.

The researchers used infrared microspectoscopy, mass spectrometry, and a chemical analysis on the ancient sea-going predator's remains to make sure what they had found was not contamination from bacteria or other modern sources.

Biggest dinosaur prints found in French Jurassic park

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Paleontologists in eastern France have reported the discovery of some of the largest dinosaur footprints ever documented, measuring about 1.4 meters to 1.5 meters (4.6 feet to 4.9 feet) in diameter.

The site of the find, high in the Jura mountains, was once a literal sauropod stomping ground: So far, 20 prints scattered on a 10-hectare (25-acre) site have been uncovered, paleontologist Jean-Michel Mazin of France's National Center of Scientific Research told The Associated Press on Wednesday.

Researchers believe there are hundreds, or even thousands, more still hidden, Mazin said.

The well-preserved footprints from the Late Jurassic period will help scientists learn more about sauropods, long-necked plant eaters that were giants among the dinosaurs. The hulking beasts who left their footprints in the mud 150 million years ago weighed 30 to 40 metric tons (33 to 44 tons) and were more than 25 meters (82 feet) long, the French research center said.

From the prints, "we can calculate their size and speed, find out about their behavior and learn how they got around," said Mazin, who is studying the site along with fellow researcher Pierre Hantzpergue. Their discovery was announced Tuesday.

Several scientists who are not connected with the project said the prints appeared to be among the biggest ever found internationally, though they noted that slightly larger tracks have been recorded elsewhere.